This proposal is a revised request for continued funding of an institutional combined pre- and postdoctoral NRSA Training Program in Immunology and Molecular pathogenesis at the Feinberg School of Medicine of Northwestern University which was funded from 1996-2006. The predoctoral training program will be run in conjunction with the Immunology and Molecular Pathogenesis graduate track, a component of the highly successful Integrated Graduate Program in the Life Sciences (IGP). The IGP will be the mechanism for recruitment of a pool of highly qualified graduate students from which predoctoral candidates will be selected. The training program is also supported by the Northwestern Interdepartmental Immunobiology Center. The training program will stress the interactive nature of immunology and molecular pathogenesis, two traditionally related disciplines. Successful research in immunology and molecular pathogenesis requires consultation and collaboration among colleagues. This program includes 23 highly productive researchers experienced in pre- and postdoctoral training who collectively hold >14 million dollars per year in research funding and who can impart both basic and clinical perspectives to a group of outstanding pre- and post-doctoral trainees. The result will be a more productive research environment, both for the pre- and postdoctoral students and for the many research projects funded by grants from the NIH and other federal and private agencies. The training grant also proposes to foster trainee interactions with scientists at other institutions through trainee travel to national meetings (to present and receive critiques on their research and to develop contacts with other scientists) and through visits of prominent scientists to the Feinberg School of Medicine as trainee-invited speakers. The training program also serves to focus the activities at the University aimed at educating students in the ethics of science and at recruiting women and minorities to graduate and post-graduate studies in immunology and molecular pathogenesis. The program requests maintaining the current four predoctoral and two postdoctoral slots. Predoctoral students will be appointed for a 2 year period at the end of the second year of graduate studies after they have completed their coursework and qualifying exams and have identified a research advisor, while postdoctoral candidates will be appointed at the outset of their training for a 1-2 year period while they apply for independent funding. Refunding of the ongoing program will give training in immunology and molecular pathogenesis at Northwestern the continuity required to maintain the momentum gained during the previous funding periods and will allow the continued supply of highly trained young investigators with primary interests in the basic mechanisms of host-parasite interactions and immune regulatory functions governing disease processes.